Most women experience uterus pain at some time during their lives, often for one of several common reasons. Pain during menstruation, called dysmenorrhoea, is caused by contractions of the uterine walls. Sometimes the lining of the uterus grows abnormally on the outside of the organ, a condition called endometriosis, which can be painful. Certain types of infections can cause uterus pain, as can fibroids, a type of benign tumor that grows in the uterine walls. Another common culprit is miscarriage.
Perhaps the most common reason that women have uterus pain is menstruation. During their periods, many women experience some amount of cramping, where the muscles of the uterus contract as it sheds its lining, or endometrium. The amount of pain experienced can vary greatly from woman to woman; for some it is very mild and short-lived, while for others it can be severe enough that they are unable to perform normal daily activities. The frequency of pain can also vary, with some women getting cramps only occasionally and others experiencing it every month.
Endometriosis, where the tissue that normally makes up the uterine lining develops outside of the uterus instead, can lead to uterus pain. The tissue, or endometrium, can grow on surrounding organs as well. It may also grow into the muscles of the uterus itself, a condition known as adenomyosis.
Another common cause of uterus pain is infection. Sexually transmitted diseases such as chlamydia can spread from the vagina and cervix up to the uterus, which may lead to abdominal discomfort or pain. When these types of bacterial infections spread through the reproductive system in this manner, it is known as pelvic inflammatory disease, or PID.
Fibroids, a type of non-cancerous growth that can develop in the walls of the uterus, may also be painful. Though smaller fibroids often cause no symptoms at all, larger ones may put pressure on nearby organs and cause pain. Women with problematic fibroids should talk to their doctor about possible options for removing them, such as endoscopic surgery.
Uterus pain may also be the result of a miscarriage. Women who have miscarriages very early in the pregnancy may have cramping similar to what they have during menstruation, and may even mistake the pain and bleeding for their period. As with menstruation, the amount of pain each woman experiences can vary greatly, and may be more intense for pregnancies that have progressed further.